1. Field of the Invention
The present invention relates to clutch-brake combinations for use in press machine environments, and, more particularly, to a brake system employing a flex disk brake.
2. Description of the Related Art
Mechanical presses of the type performing stamping and drawing operations have a conventional construction comprising a crown and a bed portion configured within a frame structure. A slide supported within the frame is adapted for reciprocating movement toward and away from the bed. The slide is driven by a crankshaft having a connecting arm coupled to the slide. These mechanical presses are widely used for a variety of workpiece operations employing a diverse array of die sets, with the press machine varying substantially in size and available tonnage depending upon its intended use.
The drive apparatus of a press machine typically includes a drive motor directly engaged to rotate a massive flywheel. The flywheel serves as the source of rotational energy that is appropriately distributed throughout the machine. A clutch assembly selectively connects the flywheel to the crankshaft during a press working cycle. Energy is removed from the flywheel and transferred to the rotating parts of the press, namely, the crankshaft. The crankshaft rotation controls the reciprocating motion of the slide. The linear driving force produced by motion of the slide is used to process a workpiece disposed between respective die shoes attached to the slide and bolster assembly. During operation, then, the rotational energy of the flywheel is used to drive the rotating parts of the machine and produce the stamped part.
The clutch typically forms part of a clutch-brake combination that coordinates the braking function and clutch function. During operation, when a press cycle is initiated, the clutch-brake combination is adapted to disengage the brake at the same time that the clutch is engaged. Following completion of the working cycle, the press operation is terminated by activating the brake, which concurrently disengages the clutch to disconnect the flywheel from the crankshaft. The brake and clutch mechanisms cooperate in an interdependent fashion such that activation of one component necessarily causes a concurrent deactivation of the other component.
In one form, the brake assembly acts to apply a braking action to the working components of the machine by stopping all of the rotating parts except the flywheel. For this purpose, the brake is adapted for selective connection to the crankshaft. In one configuration, a brake component such as a brake disk rotates in unison with a clutch component such as a clutch plate mounted to the crankshaft. A stationary brake plate is disposed between the brake disk and clutch plate.
When the brake is activated, the clutch is released from the flywheel. At the same time, the brake activation causes both the rotating clutch plate and the rotating brake disk to be brought into frictional contacting engagement with the stationary brake plate at opposite sides thereof. The frictional coupling employs brake lining material mounted on the rotating parts. In effect, the stationary brake plate becomes pinched between the brake disk and clutch plate.
Although the brake plate is designed for stationary movement in the rotational direction, the brake plate is adapted for axial movement between the adjacent rotary parts to enable the clutch plate and brake disk to center the stationary brake plate and create a full surface-to-surface abutting engagement. Otherwise, less than full contact may occur between the stationary brake plate and the rotary parts. This axial movement is typically along a dimension parallel to the longitudinal axis of the crankshaft.
The stationary brake plate is mounted on keys, pins, splines, studs or other such mechanisms to restrain rotational movement of the brake plate while allowing linear movement between the rotary parts of the clutch-brake combination. However, as the die repetitively impacts the workpiece during the stamping process, the resulting vibrational activity will pound out these spline devices and create unwanted clearances between the stationary brake plate and the splines or keys. These free and undamped clearances will allow the brake plate to move in the rotary direction during braking, thus causing impact loadings on the keys or spline devices. These impact loading forces increase with the amount of clearance. Also, this free and undamped clearance will allow the brake to move up and down due to the vibrations from the die when stamping out the parts at a high rate of speed. This action will pound out the clearance between the brake plate and key.
A flex disk brake is provided in the form of a disk structure annularly disposed about the press crankshaft and having a ring-shaped central body portion. The flex disk includes a plurality of flange-type arm portions each extending from a peripheral edge of the central ring portion in a spiral configuration which preferably forms a circumferential slot with the central ring portion. The arm portions are fixedly mounted to the press crown at respective ends thereof to establish a stationary anchor point.
The flex disk brake is fixedly mounted at its central ring portion to a brake component of the clutch-brake combination. Additionally, the arm portions are arranged to extend in a direction opposite to the typical direction of rotation of the crankshaft to allow the arm portions to offer maximum braking resistance. In a preferred form, the individual arm portions extend sufficiently in the circumferential direction to form a slot with the outer circumferential edge of the ring portion such that the preferred direction of crankshaft rotation is directed towards the closed end of the slot, although opposite rotation is also provided for.
The flex disk brake is rotationally stationary and axially flexible. Accordingly, the flex disk brake eliminates free and undamped clearances of the brake disk in the rotational direction, while simultaneously accommodating axial sliding of the brake disk due to an axially-directed flexing feature characteristic of the arm extensions.
During operation, when the brake is activated following release of the clutch, the brake component of the clutch-brake combination is axially moved into contact-type engagement with a pair of brake lining elements disposed on opposite sides of the brake component. This axial displacement or sliding is accommodated by a corresponding axial deflection of the attached flex disk brake. The braking action is applied by the brake component due to its connection to the stationary crown via the flex disk brake. In particular, the motional rigidity of the flex disk brake in the rotary direction has the effect of applying a braking torque that opposes the crankshaft rotation and eventually stops the press working members. This rotational strength of the flex disk brake substantially prevents any rotary displacement of the brake component, thereby eliminating the free and undamped rotary clearances occurring in conventional machines.
The rigid coupling of the brake component to the flex disk also ensures that the brake component will be positively located in a non-interfering, spaced-apart relationship to adjacent brake lining elements during clutch engagement (i.e., brake release). In particular, when the clutch is engaged and the brake is released, the rigid connection of the flex disk brake to the brake component serves to accurately locate the brake component between the brake lining elements, thereby ensuring the maintenance of suitable axial clearances therebetween while the brake is idle.
Moreover, following completion of the braking activity, the axial elasticity of the flex disk brake is effective in returning the brake component to its idle position concurrent with the release of the brake actuating force.
In one form, the flex disk brake has a multi-layered construction formed of several thin laminated steel plates. This arrangement of stacked plates has a flexing behavior in the direction perpendicular to the plane of the steel plates. Accordingly, the flex disk brake is configured so that the flex direction coincides with the axis of displacement of the disk component. Additionally, the rotary motion of the brake component (and crankshaft) is parallel to the direction of greatest strength and rigidity in the flex disk brake, namely, the plane of the laminated steel plates, thereby offering the maximum possible braking action.
The invention, in one form thereof, is directed to a brake system for use in a machine environment. The brake system includes a brake member disposed within the machine and a flex brake unit coupled to the brake member. The flex brake unit comprises a brake disk coupled to the brake member, and at least one finger element extending from the brake disk. At least one of the finger elements is coupled to a stationary member of the machine.
In one form, a mechanism is provided to selectively connect the brake member to a rotary member of the machine.
In one form, at least one of the finger elements generally extends at least in part in a first generally circumferential direction of the brake disk. This first circumferential direction is generally opposite to a direction of rotation associated with operation of a rotary device of the machine.
In one form, the flex brake unit includes a flexing property having an axial directivity. In a preferred feature, the flexing property has a directivity substantially parallel to an operative displacement axis associated with the brake member.
In one form, the flexing property is preferably sufficient to enable movement of at least the portion of the brake disk coupled to the brake member. In another form, the flexing property is sufficient to enable displacement of the brake disk relative to a respective stationary portion of at least one corresponding finger element. In yet another form, the flex brake unit is formed and configured to be operationally axially flexible and substantially rotationally stationary.
The invention, in another form thereof, is directed to a brake system for use in a machine environment. The brake system includes a movable brake component disposed within the machine, and a connection means having a stationary portion and a movable portion. The movable portion is connected at least in part to the brake component.
In one form, the movable brake component further includes a brake disk annularly disposed about and selectively connectable with a rotary component of the machine.
In one form, the connection means further includes a flexible portion connecting the stationary portion and the movable portion.
In another form, the connection means further includes a disk means coupled to the brake component, and a first means for connecting the disk means to a stationary part of the machine. The first means preferably includes at least one connection element each providing a respective connection between the disk means at a periphery thereof and the stationary machine part. Each connection element includes a bent portion, which generally extends at least in part in a direction generally opposite to a direction of rotation associated with operation of a rotary component of the machine.
In yet another form, the connection means is adapted with a flexing property enabling movement of the movable portion thereof relative to the stationary portion thereof, according to a flexing action exhibited by the connection means.
In yet another form, the connection means is formed and configured to be operationally axially flexible and substantially rotationally stationary.
In one form, the machine environment includes a press machine having a crankshaft, the brake component includes a brake disk, and the press machine includes a mechanism to selectively connect the brake disk to the crankshaft.
The invention, in another form thereof, is directed to a brake system for use in a machine environment. The brake system includes a brake component disposed within the machine, and a spider mechanism connecting the brake component to a stationary part of the machine.
In one form, the spider mechanism further includes a disk coupled to the brake component, and a plurality of spider arms disposed about a periphery of the disk and coupled to the stationary part of the machine. Each spider arm preferably has a flexibility characteristic. The flexibility characteristic enables movement of the disk relative to the stationary part of the machine, in response to operative movement of the brake component.
In one form, each spider arm generally extends at least in part in a direction generally opposite to a direction of rotation associated with operation of a rotary device of the machine.
In another form, the spider mechanism is formed and configured to be operationally axially flexible and substantially rotationally stationary.
The invention, in another form thereof, is directed to a brake system for use in a machine environment. The brake system includes a brake component disposed within the machine, and an axially flexible connection device connecting the brake component to a stationary part of the machine.
In one form, the connection device further includes a body member coupled to the brake component, and a plurality of flexible spider arms disposed about a periphery of the body member and coupled to the stationary machine part. At least one of the spider arms generally extends at least in part in a direction generally opposite to a direction of rotation of a rotary device of the machine.
The flexibility of the spider arms is adapted to enable movement of the body member relative to a respective stationary portion of at least one corresponding spider arm.
In another form, the connection device further includes a spider mechanism including a plurality of flexible spider arms.
The invention, in yet another form thereof, is directed to a press. The press comprises a crown and a bed; a movable slide disposed for operative movement in opposed relation to the bed; a frame to guide operative movement of the slide; a flywheel; a driveshaft; a clutch assembly to selectively connect the flywheel and the driveshaft; and a brake assembly to selectively brake the driveshaft. The brake assembly includes a brake disk, a mechanism to selectively couple the brake disk to the driveshaft, and a flexible spider means connecting the brake disk and the crown.
In one form, the flexible spider means further includes a body member coupled to the brake disk, and a plurality of flexible spider arms extending from the body member and coupled to the crown. In one form, the spider arms are disposed about a periphery of the body member. The body member preferably has a generally disk shape.
The flexibility of the spider arms enables operative movement of the body member relative to a respective stationary portion of at least one corresponding spider arm.
In one form, at least one of the spider arms generally extends at least in part in a direction generally opposite to a direction of rotation of the driveshaft.
In another form, the spider means is formed and configured to be operationally axially flexible and substantially rotationally stationary.
The invention, in yet another form thereof, is directed to an article of manufacture for use as a brake device in a brake unit of a machine. The article includes a generally disk-shaped body member, and a plurality of arcuate finger elements each extending from the body member. Each finger element has a flex region normally defining a generally planar structure comprising a plurality of plate members disposed in a layering arrangement. The layering arrangement defines a flexing axis directed generally orthogonally to a planar dimension thereof.
One advantage of the present invention is that the flex brake unit eliminates free and undamped clearances in the rotational direction.
Another advantage of the invention is that the flex brake unit features both an axial flexibility to accommodate deflection of the brake disk during brake activation, and a rotational immovability that establishes a stationary braking force.
Another advantage of the invention is that the flex brake unit offers substantially no impact loading in the rotary direction during braking, since the unit is rotationally stationary.
A further advantage of the invention is that the flex brake disk in one form thereof includes a multi-layered steel construction that enables the flex brake to readily deflect in the axial direction during brake activation, while providing significant torquing opposition or rigidity along its planar dimension, which coincides with the direction of rotation of the brake-clutch combination.
A further advantage of the invention is that the flex brake disk features an elastic flexibility that provides a spring-type action which restores the deflected flex brake disk to its disengaged position following activation of the clutch and simultaneous deactivation of the brake.
A further advantage of the invention is that the problems associated with conventional brake splining mechanism, namely, the formation of clearances due to the vibration-related pounding out of the splines, is not present in the flex brake unit due to the significant torquing opposition exhibited by the flex brake disk that makes it rotationally stationary.
A further advantage of the invention is that the flex brake unit provides a braking configuration that makes it immune to the effects of vibration traveling through the machine and the related clearance-type problems.